FLAVAN-4-OL CONCENTRATION IN LEAF TISSUES OF GRAIN MOLD SUSCEPTIBLE AND RESISTANT SORGHUM PLANTS AT DIFFERENT STAGES OF LEAF DEVELOPMENT

Fully opened youngest leaves from sorghum [Sorghum bicolor (L.) Moench] germ plasm accessions, exhibiting both resistance and susceptibility to the grain mold complex, were collected at 56, 63, and 70 days after emergence (DAE) of plants. They were extracted in methanol followed by acidified methanol and analyzed for flavan-4-ols. Methanol and acidified methanol extracts of leaves of mold-resistant accessions contained at least 3-fold higher concentrations of flavan-4-ols than susceptible accessions at 56, 63, and 70 DAE. The concentration of flavan-4-ols was monitored in the flag leaves of mold-resistant accessions that had no testa at 77, 84, 91, and 98 DAE, and it decreased sharply at or after 77 DAE. The estimation of concentration of flavan-4-ols in sorghum leaves, therefore offers scope for screening sorghum accessions for their grain mold resistance.